I guess the problem only arises for example in my case, whereby I extend the grid's autoSize() to do a getView().fitColumns().

This results in the problem whereby the height is correctly computed via updateWrapHeight, while width is remains as the original width style defined in the grid container's html markup. Subsequent calls to autoSize() will space the columns out nicely once the grid is actually rendered.

Visually, what happens is that at the first moment that the grid is displayed in the layout, the height is correct, but all the columns are squashed into the originally defined width. A delayed call to autoSize() can be added to space out all the columns correctly thereafter, but incurs quite an extra hit on cpu cycles, as well as a visual glitch whereby the columns appears squashed for a split second then expand out to occupy the auto width space.

In the meantime, I've overriden updateWrapHeight() to simply always setSize to both the computed height and width - works great now.